Check valve



,produced ata minimum'cost; Another object of my invention is to providevention, is relatively inexpensive.

Patented Aug. 27, 1940 UNITED PATENT OFFICE My invention relates tocheckfvalves; r, An object of my invention is to provide" checkvalve ofsimple construction which lll y' be a check valve in j A further objectof my inventionis t6 provide v actuating the valve incertain positionsthereof;

My invention .further contemplatesffa check valvef-operable in ahorizontal,",vertical; or any,

other desired position. I

Otherob-jects and advantages of my inven? tion will be pointedout in theclaims at the end of the specification and will be apparent from thefollowing description, when 'taken in conne'c-" tion with theaccompanying drawing; in which;

The-single figure'isa side elevation; partly in section, showingthep'artsof my novel check.

valve. v U w The check valve of my invention comprisesa' valve bodygenerally indicated by the numeral ll'," having an inlet opening I2, anoutletopening l3, and a third opening I4, preferably in" axial.alignment with the inlet opening. One oi the important features of myinvention lies'iin' the fact that the valve body may be a standardIT-fitting, in which the valve parts of, the valve may beassembledeasilyand at'a mini mum of expense. In most check valves with which'I amfamiliar nary T-fitting, forming the valve body of my in- The inletopening I 2 is threaded. as indicated at 53, as is usual in aconventional T-fitting and is adapted to receive a threaded bushing orfitting H. An inlet pipe 18 is preferably threaded into the bushing orfitting IT. The inner threaded wall ofa valve body is machined, asindicated at Ila, to provide a shoulder 15 constituting part of a valveseat Illa. The remainder of the valve seat is formed by the innerannular end of the bushing 11 which is machined to lie in the same planeas the shoulder 15.

The valve, generally indicated by the numeral l9, comprises asubstantially flat valve disc 2|, with which is preferably formedintegral a pilot tube or cylinder 22, extending substantially normal tothe plane of the. disc. The valve disc is generally circular and isadapted to seat upon the valve seat I 8. The lower end of the cylinisthreaded, as shown at 28, and

the valve body is a'relative'i ly expensive specialcasting whereasan'lordiden 22 is closed by the valve disc as fshown'at 23 while the,upper 'end is open, and is substanf tially closed b-ya caplor collar 24.

Extending into the cylinder, 22 is the endflportion ofv an adjustablepilot rod or valve guide rod 26. Preferablyfthe portion of the valveguide which e'xtendsinto the cylinder 22 is enlarged, as shownin thedrawing, to provide a piston 21,

wh ich1 looselygfits in the cylinder 22 and ex:

tends loosely through an aperture formed in the cap 24. The upper end ofthe valve guide, roc'f provided with'a screw driver receivingslot 29.-'1 The thii'dopening l4, which is in axial align} ment with the inlet}opening I2,- is threaded to: receive 'a, pipe plug'fil, which closes theopening The plug is substantially centrally tapped, as in dicated at32,tofireceive the valve guide rod and has 'a counterbore33 for a purposelater, w be described] A lock nut and washer assembly 3'4 serves to holdthe valve guide rod vinjany desired adjusted position. The pipeplugf3latj36 is tapped to receivea vent pipe (notfshown) for the purposeof permitting ,the escapeof any ai'n' trappedjin thevalvebody. I W

Secured" to thecylinder 22, as shown at 31, and to'the'valvedisc, asshown at 38, is a sub'i stantially cup-shaped inverted member 39, whichencloses afloat chamber 49. The float cha rnher is sealediagain'stjleakage of fluid. fromjthegg valve chamber into'the floatchamber,] or from,v the cylinder into the float chamber, asindicated at31 and .38. Extending between the cylinder 22 and thevalve chamber andpassing throu'gh the float chamber isa tube '42,whi ch,j"tqgetheif guiderod',"ffor1ns with the cylinderandthe'; valve v a hydraulic cushion'or'dash pot for eliminating chattering of the valve, as will be presentlydescribed. Encircling the valve guide rod and seated in the counterbore33 and on the cap 24 is a compression spring 43, which serves to retainthe valve in a closed position.

While the check valve of my invention is of general applic'ation'and maybe employed in any fluid system requiring a valve which permits onlyunidirectional flow of fluid, it .is particu-' larly adapted for thecold water return line of a'boiler system. With the valve in theposition shown in the drawing, the float chamber 4| acts to counteractthe weight of the valve *disc 12!, the cylinder 22 and the action of thespring 53. However, when the valve is used in this position, the floatchamber 4i and the spring 43 may be dispensed with in someinstallations, as the valve is sufliciently heavy so that it will seatby gravity. 1 When, however, the valve is mounted in an invertedposition, which is sometimes useful in connecting the cold water returnpipe with the top of a boiler in order to obtain the most eificient heattransfer arrangement with the cold water striking the hottest portionsat the top of the boiler, the float chamber is extremely advantageousforclosing the valve against the action of gravity. With the valve in theinverted position the spring i3 may be eliminated, if desired, sincethefloat chamber is sufliciently buoyant to close the valve against theaction of gravity.

The check valve of my invention may be also a mounted in any otherposition besides itsvertical and u'p-side-down position, should other.positions of thevalve be desired. For example, the

valve may be mounted on its side. When the valve is mounted on its side,the float chamber 4| counterbalances theweight of the valve and tendstov maintain it substantially in axial alignment with the valve guiderod. In thisposition of" the valve thespring 43 closes the valve when nopressure exists in thejinlet pipe I8. When prBSSure exists in the inletpipe, as, for example,

i when fiuid'is pumped through the system,v the valve disc is raisedfrom itsv seat against the action of the spring 43. I During the openingmovement of the valve the 1 cylinder 22 moves with respect to. the valveguide j rod so .that liquid in the cylinder flows out throughthe tube42, thereby delaying the action of the valve during the opening movementand eliminating chattering of .the valve. During the closing movement ofthe valve, the cylinder moves downward with respect to the valve guiderod creating aslightly sub-atmospheric pressure in the, cylinder, thusdelaying the closing of the valve while water is drawn in through thetube 42. The valve thus seats with a minimurn'of chattering and noise.

In case of failure of the pump, or when it is desired to rely on thermalcirculation, the lock nut 34, may be loosened and the valve guide rod. Ithreaded upward (as viewed in the drawing), to

thereby cause the valve guide rod to lift the valve off its seat andretain the valve in open position I claim:

1. A valve structure comprising a conventional T fitting having theusual axially aligned open- 1 ings and an opening perpendicular to theaxially aligned openings serving as an outlet for the valve, a bushingthreaded in one of said axially aligned openings adapted toreceive aninlet pipe, a plug threaded in the other of said 'axially alignedopenings, a valve guide rod threaded in said plug and extending into theT fitting, a valve adapted to seat on said bushingand having a hollowcylinder formedintegral therewith, said guide rod extending into saidcylinder and said cylinder having an outlet opening into the T fittingenabling the cylinder and rodto act as a dash pot, and a'fioat carriedby said valve.

2. A valve structure comprising a conventional T fitting having theusual axially aligned openings and an opening perpendicular to theaxially aligned openings serving as an outlet for the valve, a bushingthreaded in one of said axially aligned openings adapted to receive aninlet pipe,

a plug threaded in the other of said axially aligned openings, a valveguide rod threaded in said plug and extending into the T fitting, avalve adapted to seat on said bushing and having a hollow cylinderformed integral therewith, said guide rod extending into said cylinderand said cylinder having an outlet opening, into the T fitting enablingthe cylinder and rod toact as a dash pot, a spring surrounding saidvalve rod normally adapted to close the valve, and a float ceive aninlet pipe, a plug threaded into the other of said axially alignedopenings, a .valve guide rod threaded in and extending through saidplug, a valve-adapted to seat on said bushing and having a hollowcylinder secured thereto, said guide rod extending into said cylinderand said cylinder having an outlet opening into the T fitting enablingthe cylinder and rod to act as a dash pot, said axially aligned openingsbeing substantially of the same diameter whereby the valve, cylinder,and guide rod may be removed as a unit from the fitting and with theplug, and means on the externalend of said plug for enabling adjustmentof the valve guide rod in the cylinder without removing the plug, aspring normally urging the valve tov a closed position and afloatcarried by said valve.

' FRANK M. HARM.

